Technical Field
The present invention relates to a device for circularizing croissant dough, a device for forming croissant dough in a U-shape, a system for producing croissants, a method for circularizing croissant dough, and a method for forming croissant dough in a U-shape, each of which is suitable for production on a large scale.
Background Art
Croissants have been popularly known for their unique shape of a crescent or a circle in that the tips of the crescents are connected. Conventionally, a machine for forming croissants in such a shape has been developed. However, though the croissant dough is formed in that shape, it swells at a later process (a rising or baking process) to return to its original shape, such as a crescent or a bar. Thus a method for putting one tip of the crescent on the other tip and for bonding them by pressure has been known, to thereby maintain the shape of the croissant dough.
For example, by a method disclosed by European Patent Application Publication No. 0490190 (Publication 1), croissant dough is circularized by a pair of bending arms. One of the bending arms is equipped with a tab for lifting. When the pair of bending arms are swung about their respective base ends, the croissant dough that is formed like a bar by being rolled up is formed to follow the shape of the bending arms. The bending arm that is equipped with the lifting tab moves upward when it swings. Thus one end of the croissant dough is lifted by the lifting tab. Therefore, when the pair of bending arms swing so that their front ends close, the tips of the croissant dough that is circularized to follow the shape of the bending arms overlap. Subsequently, the portions that overlap are pressed by a plunger to be stuck together.
By a method disclosed by International Publication No. WO 2011/144191 (Publication 2), croissant dough is circularized by a pair of retaining jaws and a pair of shaping jaws. Both ends of bar-shaped croissant dough that has been rolled up are clamped by the retaining jaws and the shaping jaws. The pair of retaining jaws and the pair of shaping jaws are moved by a pair of pivot carriers so as to circularize the bar-shaped croissant dough. One of the pivot carriers moves upward when it swings. Thus one end of the croissant dough is lifted so that the ends overlap. Subsequently, the portions that overlap are pressed by a plunger to be stuck together.
Further, it is preferable to form symmetrical croissants. However, neither Publication 1 nor 2 discusses croissants being symmetrically formed. Japanese Patent No. 2747778 (Publication 3) discloses a method for symmetrically forming croissant dough. By that method bar-shaped croissant dough that has been rolled up passes through a space between a pair of hourglass rollers to be moved to the center in a conveyor that conveys the dough. The croissant dough is pushed at the center of its back side that is located at the center of the conveyor by a member that moves along the center of the conveyor in the direction for conveyance. It is squeezed into a space between a pair of belts that inwardly incline in the downstream direction. The pair of belts form the croissant dough in a symmetrical shape.
However, by the method of Publication 1, since the pair of bending arms swing about the base ends, the croissant dough cannot pass through the space between the bending arms. Thus the bar-shaped croissant dough is dropped into that space from the rollers that are located above the bending arms. Since by such a method the position of the bar-shaped croissant dough is not constant, it is difficult to form it in the required shape. Thus the method is impractical.
By the method of Publication 2, setting the forces to clamp the croissant dough by the retaining jaws and the shaping jaws is difficult. The portion of the croissant dough that is clamped is often crushed. Further, since the croissant dough is clamped to be lifted, the operating speed is limited and the capacity for production is restricted. Further, the device for carrying out the method is complicated and large. These are problems.
By the method of Publication 3, since the croissant dough that has been rolled up has a thick center that is difficult to bend, it is not always formed symmetrically, depending on its Elasticity (the hardness of the inside of the dough). (The term “Elasticity” means elasticity or hardness when it is inwardly pressed.) This is a problem.
The present invention aims to provide a device and a method for quickly and stably circularizing croissant dough.
The present invention also aims to provide a device and a method for forming bar-shaped croissant dough in a U-shape, then quickly and precisely arranging both legs of the U-shape to have the same length, and producing croissants in the required shape.